Abstract: China's 13th Five-Year period (2016-2020) is the critical period for building a moderately prosperous society, requiring local governments to abandon the only GDP rate theory and cite the" new normal "economic transformation as the kernel in development. In addition, the proportion of the Tertiary Industry should be increased as well in order to integral elevate the industrial competitiveness of China. Therefore, how to effectively and quickly complete the transformation of the economic structure in China has been paid widespread attention by scholars. However, previous studies focusing on this problem are mostly lack of the identifications of input proportion for various industries and the entire stability of the industrial structure distribution. Based on this background, the optimization of the Third Industry structure is taken as the research subject, and the investment portfolio theory and Entropy-Controlled principle are introduced into this problem, in order to provide decision support for government departments to establish scientific industrial structure policies in accordance with the 13th Five-Year Plan. Meanwhile, a new multi-objective industrial structure optimization model solved by the Pareto based GA algorithm is developed, in which the synthesis entropy is used to comprehensively measure the quantity and quality of the industrial structure development, and the industries within the Third Industry are seen as a group of securities. In addition, five aspects, including the economic output, energy consumption, carbon emissions, employment level, and the equity of industrial distribution, are taken into account. Moreover, a case study of Beijing City is also implemented, in which the authors used the proposed model, adopting the data from 2013, to predict and adjust the tertiary industry structure in 2014. The results show that the gained several groups of industrial structural portfolios are relatively better than the actual data with respects to above five considered aspects, accordingly proving the effectiveness of the proposed model and the conclusion that through reasonable adjustment of industrial structure it is possible to improve the economic output, employment level and the equity of industrial distribution without increasing energy consumption and carbon emissions.

Key words: tertiary industry structure, portfolio theory, entropy-controlled principle, I-O table, multi-objective optimization, GA